<template>
  <div class="Tizi-infinite-loading" ref="target">
    <div class="loading" v-if="loading">
      <span class="img"></span>
      <span class="text">正在加载...</span>
    </div>
    <div class="none" v-if="finished">
      <span class="img"></span>
      <span class="text">亲，没有更多了</span>
    </div>
  </div>
</template>

<script>
import {ref} from 'vue'
import { useIntersectionObserver} from '@vueuse/core'
export default {
    name:'TiziInfiniteLoading',
    props : {
        loading : {
            type: Boolean,
            default: false
        },
        finished : {
            type: Boolean,
            default: false
        }
    },
    // setup (props, {emit}) {
    //     const container = ref(null)
    //     useIntersectionObserver(
    //         container,
    //         ([{ isIntersecting }], dom) => {
    //             if (isIntersecting) {
    //                 if (props.loading === false && props.finished === false) {
    //                     emit('infinite')
    //                 }
    //             }
    //         },
    //         {
    //             threshold:0
    //         }
    //     )
    //     return { container }
    // }
    setup (props, { emit }) {
    const target = ref(null)
    // 监听target是否进入可视区
    useIntersectionObserver(
      target,
      ([{ isIntersecting }]) => {
        if (isIntersecting) {
          console.log('进入可视区了')
          // 触发加载事件条件：请求加载完成，数据加载完毕
          if (!props.loading && !props.finished) {
            emit('infinite')
          }
        }
      }, {
        threshold: 0
      })
    return { target }
  }
}
</script>

<style lang="less" scoped>
.Tizi-infinite-loading {
  .loading {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 200px;
    .img {
      width: 50px;
      height: 50px;
      background: url(../../assets/images/load1.gif) no-repeat center / contain;
    }
    .text {
      color: #999;
      font-size: 16px;
    }
  }
  .none {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 200px;
    .img {
      width: 200px;
      height: 134px;
      background: url(../../assets/images/none.png) no-repeat center / contain;
    }
    .text {
      color: #999;
      font-size: 16px;
    }
  }
}
</style>